Ultrasonic Security System using Atmega644 microcontroller

This portable security system is built based on Atmega644 microcontroller. It can detect intruders based on their physical presence. The system uses URM37v3.2 ultrasonic sensor which is connected to MCU through rs232 serial communication. To rotate sensor for wide coverage range, the system is equipped with Parallax servomotor. For user interface, there are LCD and keypad wired to PORTC and PORTA of MCU.

How It Works? The ultrasonic transmitter periodically emits ultrasonic signals into an open area in front of it. A rotating servomotor is used to allow the sensor (transmitter and receiver pair) to cover wide range (roughly 180 degrees). If the signal hits a physical object, it will be reflected back and the receiver part of the sensor will capture it and detect its distance.